Fig. 1From: A novel semiautomated method for background activity and biological tumour volume definition to improve standardisation of 18F-FET PET imaging in glioblastomaSchematics of the algorithm for the two methods. Mirror-image method involving an iterative optimisation process. Guided crescent-shape method involving a linear process. FET = 18F-Fluoroethyl-l-tyrosine; TBR = tumour-to-brain ratioBack to article page